Lubricants



2,898,331 Patented Aug. 4, 1959 LUBRICANTS Amos Dorinson, Homewood,111., assignor to Sinclair Refining Company, New York, N.Y., acorporation of Maine No Drawing. Original application August 3 1956,Serial No. 602,061. Divided and this application February 27, 1958.Serial No. 721,327

2 Claims. (Cl. 260-125) This invention relates to sulfur-chlorinatedesters of chlorendic acid, and particularly to the use of such esters inmineral oils to provide extreme pressure lubricants and metal-workingoils having improved properties. This invention further relates toextreme pressure lllbllcants of improved load carrying ability whichsatisfy a:

the requirements demanded in the lubrication of bearings, gears, and thelike, subjected to heavy loads per unlt area of surface.

The present invention is particularly concerned with cutting oils usedin broaching, gear cutting, hobbmg, planing and similar operations inwhich metal is removed from the work piece at a comparatively low rate,e.g. at cutting speeds of to 20 surface feet per minute. The metal chipsremoved vary in thickness from 0.005 to 0.0005 inch. A major objectiveof cutting operatlons of this type is the achievement of a good surfacefinish, and, therefore, one of the functions of a cutting oil used insuch operations is to improve the surface finish obtamed.

Certain short chain chlorinated compounds such as carbon tetrachloride,ethylene dichloride and diisobutylene dichloride are known to beespecially effective as additives for broaching and gear cutting oils.Although an excellent surface finish can be obtained on work pieces bythe inclusion of carbon tetrachloride in-broaching and gear cuttingoils, this compound is notsuit'ableas a cutting oil additive for tworeasons. volatility carbon tetrachloride is rapidly lost by evaporationfrom the cutting oil during use thus necessitating close control of theconcentration and frequent replenishment with fresh carbontetrachloride. Second, carbon tetrachloride is a toxic substance whichcauses severe physiological damage when inhaled as a vapor or whenabsorbed through the skin by contact. Ethylene dichloride is also highlyvolatile. Diisobutylene dichloride, which might be used as a substitutefor carbon tetrachloride due to its lack of toxicity, is objectionablebecause of its highly unpleasant odor which could not be tolerated forthe length of an average working day. Therefore, a need exists for anon-toxic, non-volatile, substantially odorless, mineral oil-solubleadditive which imparts extreme pressure properties to a cutting oilcomposition.

In accordance with the present invention I have discovered that valuableextreme pressure additives can be prepared by sulfur-chlorinatingunsaturated esters of chlorendic acid and that the addition of suchadditives to mineral lubricating oils provides extreme pressurelubricating compositions of improved load carrying ability underconditions of high mechanical loading. As cutting oils or metal workingfluids, mineral oils which contain sulfur-chlorinated esters ofchlorendic acid are useful in reducing the surface roughness of machinedparts.

The oil-soluble sulfur-chlorinated esters added to mineral lubricatingoils in preparing lubricating compositions of this invention can beobtained by sulfur-chlorinating First, due to its an oil-soluble esterof chlorendic acid of the following formula:

in which R is an unsaturated aliphatic, including cycloaliphatic,hydrocarbon group containing 3 to 20 carbon atoms and R is hydrogen orthe identical or non-identical member selected from the same group as R.More specifically, the unsaturated members include alkenyl groups suchas allyl, oleyl, cyclohexenyl and ester groups from unsaturated alcoholsderived from acids such as linoleic, myristoleic, cinnarn-ic, angelicand the like, which unsaturated members can, if desired, be substitutedas with chlorine for instance. Although the monoesters can be employed,the preferred esters of chlorendic acid are diesters and particularlythose in which the ester groups are mono-olefinic and contain from 16 to18 carbon atoms. A preferred diester can be obtained from theunsaturated alcohols derived from sperm oil. The esters can be preparedby any suitable method as, for example,

7 by reacting chlorendic anhydride with an excess of the appropriateunsaturated alcohol. The esterification reaction can be carried out inthe presence of acatalyst such as p-toluene sulfonic acid until thetheoretical amount of water has been removed. Alternatively, chlorendicacid may be used instead of the anhydride and in this method two molesof water are evolved for each mole of chlorendic diester formed. Thewater of reaction may be removed azeotropically by distillation with asolvent such as benzene or toluene.

The sulfur-chlorination of the chlorendic acid ester is accomplished byreacting each mole of chlorendate ester with about .5 to 2 moles of asulfur chloride such as sulfur monochloride or sulfur dichloride at atemperature in the range of about to 300 F. Frequently, the exothermicheat of reaction will maintain the reaction mixture within the desiredtemperature range although in large scale preparations it may benecessary to use external cooling means.

In oil blends which are used as metal working fluids in operations suchas planing, breaching, gear cutting and the like, the amount of additiveemployed can depend upon the particular ester in the additive. Foresters of high molecular weight, for example, sulfur-chlorinated oleylchlorendate diester, the amount employed will usually be about 9 to 35%by weight whereas for the lower molecular weight esters, such assulfur-chlorinated diallyl chlorendate, the amount used in general willrange from 5 to 30% by weight. The compounding of oils for extremepressure lubricants frequently requires about 0.5 to 10% of thesulfur-chlorinated chlorendate ester. These percentages are based .onthe weight of the mineral oil present. The manner in which thesulfur-chlorinated esters of chlorendic acid are prepared and theproperties of lubricating oils containing the esters are illustrated inthe following examples which are not to be considered 1000 gramsofcommercial oleyl alcohol (hydroxyl numher 214, iodine number 83) wasdissolved in 1000; cc.- of xylene and 10 grams of p-toluene sulfonicacid were added as a catalyst. The mixture was heated to r flux for 10hours until 44 cc. of water had been collected in a Dean-Stark trapattached to the esterification apparatus.

The reaction mixture was then washed once with 0.25 N KOH in 1:1alcohol-water and twice with 1:1 alcohol water. After clarification byfiltration, the reaction mixture was freed of xylene by distillation andthe last traces of solvent were removed under vacuum at a pottempearture of 300 F. The reaction product was a dark oily liquid withthe characteristics listed below.

Percent chlorine -1 24.0

Acid number 0.28

Saponification number 127.9

Iodine number 50.1

EXAMPLE II Preparation of allyl chlorendate diester A mixture of 1500grams chlorendic anhydride dissolved in 2000 cc. of allyl alcohol withgrams of p-toluene sulfonic acid as a catalyst was refluxed for 32 hoursand the excess allyl alcohol was removed by distillation. The residuewas taken up in a mixture of pentane and benzene and was washed firstwith aqueous KOH and then with water. The solvent was distilled off,first at atmospheric pressure and finally at 23 mm. pressure. Theproduct was a dark viscous liquid having the following characteristics.

Percent chlorine 44.8 Acid number 0.10 Saponification number 236.8Iodine number 107.1

EXAMPLE III Sulfur-chlorination of oleyl chlorendate diester product, athick, sticky, dark brown substance at room temperature, contained 5.85%sulfur and 25.8% chlorine.

EXAMPLEIV Sulfur-chlorination of allyl chlorendate diester To 600 gramsof allyl chlorendate diester, 115 grams of sulfur monochloride weregradually added at a temperature of 195210 F. The reaction mixturethickened progressively and eventually became so viscous that furtherstirring was impossible. This tacky, semi-solid matenal contained 7.18%sulfur and 44.7% chlorine.

EXAMPLE V Compounded oils containing sulfur-chlorinated oleylchlorendate diesters Compounded oils were prepared withsulfur-chlorinated di-oleyl chlorendate, as prepared in Example III, byblending the additive into acid-refined Coastal naphthenic 0118 at 150F. to 210 F. The additive remained completely dissolved in the oil atroom temperature. The

following blends were made up in mineral oils of difierent viscosities.

4 EXAMPLE v1 Compounded oils containing sulfur-chlorinated allylchlorendate diester Eighty parts of the sulfur-chlorinated diallylchlorendate of Example IV were mixed "with 20 parts of benzene to aid inblending the additive into oil. Seven hundred and eighty-seven grams ofthis mixture were added to 5025 grams of an acid-refined Coastal oil of175 seconds viscosity at F. It was found necessary to add 1839 grams ofbenzene to keep the sulfur-chlorinated diallyl chlorendate completelydissolved in the oil at room temperature. The final blend, which had8.25% of sulfurchlorinated diallyl chlorendate incorporated therein,contained 0.79% sulfur and 3.28% chlorine; and had a viscosity of 96.6SUS at 100 F.

EXAMPLE VII Sulfur-chlorinated chlorendate esters as metal-workingadditives The advantages obtained by employing the lubricatingcompositions of the present invention as cutting oils becomeparticularly apparent in cases where the surface finish requirements forthe work piece are unusually stringent. The effect of oil blendscontaining sulfurchlorinated oleyl chlorendate diester as a cutting oilwas demonstrated by means of an orthogonally cutting planer operation.As shown below, the various oil blends prepared in accordance withExamples V and VI were rated according to the surface roughness of thecut surface as determined by a profilometric measuring instrument.Results are shown in Table I below.

Oil blends containing sulfur-chlorinated oleyl chlorendate diester weretested for extreme-pressure load carrying ability in the Falex lubricanttesting apparatus. Also an oil blend containing 26% by weight of anonsulfur-chlorinated oleyl chlorendate diester was tested. In this testan uncompounded mineral oil does not allow the test to run for thethree-minute breakin period at 300 lbs. load without failure. As can beseen, the sulfurchlorinated diesters provide extreme pressure lubricantsof improved load carrying ability.

TABLE II Oil Blend Percent Failure Additive Load, Lbs.

1 Blends prepared as in Example V.

9 26% oleyl chlorendate in oil. 31 Did not fail at load limit of theapparatus.

I claim: 1. A sulfur-chlorinated oil-soluble ester of chlorendic acidproduced by reacting a sulfur chloride and an oilsoluble chlorendic acidester in a ratio of about .5 to 2 moles of sulfur chloride to 1 mole ofa chlorendic acid ester wherein said ester group is an unsaturatedaliphatic hydrocarbon radical containing from 3 to 20 carbon atoms.

6 2. The sulfur-chlorinated oil-soluble ester of claim 1 in which theester is a diester in which each ester group contains from 16 to 18carbon atoms.

No references cited.

1. A SULFUR-CHLORINATED OIL-SOLUBLE ESTER OF CHLORENDIC ACID PRODUCED BYREACTING A SULFUR CHLORIDE AND AN OILSOLUBLE CHLORENDIC ACID ESTER IN ARATIO OF ABOUT .5 TO 2 MOLES OF SULFUR CHLORIDE TO 1 MOLE OF ACHLORENDIC ACID ESTER WHEREIN SAID ESTER GROUP IS AN UNSATURATEDALIPHATIC HYDROCARBON RADICAL CONTAINING FROM 3 TO 20 CARBON ATOMS.